Fault Localization of Timed Automata Using Maximum Satisfiability

Timed automata are formal models for systems whose real-time behavior is a major concern, and practical model checking tools are available for them. Although these tools are effective to detect faulty behavior, localizing root causes of faulty timed automata requires a costly manual task of studying counter-examples. This paper presents an automatic fault localization problem. The proposed approach follows the Reiter’s model-based diagnosis theory to employ the consistency-based method, and details the method to show how the Reiter’s general theory is applicable to timed automata. In particular, the proposed method introduces a modest assumption on the failure. The paper discusses how the failure model and properties to be checked affect the formula used in the consistency-based fault localization method.